Tool for truing up crank shafts



I K. R. PETERS. TOOL FOR TRUING UP CRANK SHAFTS.

APPLICATION HLED,MAY 19, I920.

I llvvsm'ore Mv/fffefani Patented Feb. 14, 1922.

[ATTORNEYS iJhll'E'EQ STATES PATENT OFFICE.

KARL R. PETERS, OE .HILADELPHIA, PENNSYLVANIA.

TOOL FOR, TRUTJTG U? CRANK SHAFIS.

1,4&06,756.

- Application filed May 19,

Z '0 all whom it may concern:

Be it known thatl. KARL Farms, a citizen of the United States, and a resident of the city of Philadelphia, in the county of Philadelphia, State of Pennsylvania, have invented a certain new and useful Tool for Truing Up Crank Shafts, of which the following is a specification, reference'being had to the accompanying drawing.

My invention relates to a truing-up tool provided with a plurality of cutting elements arranged in circular order and adapted by suitable means to be simultaneously or universally moved radially during the operation of the tool. v

Among the objects of the invention is to provide a tool of the character above-mentioned for grinding or cutting bearings on crank shaft particularly those used in automobile engines, without necessitating the removal of the shaft from the engine; which is adapted'to be opened about a hinge or pivot to enable it to be inserted between the arms of the crank shaft respectively adj acent the ends of the bearing to be operated on and then closed over the bearing for retat-ion thereon, which is so constructed that its several operating parts are held in proper relation at all times whether the tool is in open or closed position and which comprises means adapted to feed the cutters of the tool universally or in unison for equal distances in radial directions while the tool is in operation.

My invention further contemplates the provision in a tool of the character aforesaid of a feed control element suitably divided to permit the component parts to separate when the tool is opened and to close together when the tool. is closed so as to form a continuous single operative element; further, the provision of cutting means arranged in diametrically opposed pairs effective to constantly and automatically maintain the tool assembly in centered position on the bearing whereby the cutters perform both the function of cutting and of guiding the tool in its movement over the bearing surface, thereby avoiding, the necessity of the use of additional guiding means such as has hitherto been found essential in tools of this general character and the possibility of the'tool being thrown out of alignment by the jamming of chips or burrs between such guiding element and the surface of the bearing. Moreover, my'improved $901 is so constructed as Specification of Letters Patent. Patented Feb. 14;, 1922.

3.920. Serial No. 382,835.

to be thinner than the length of the bearing to be cut or ground, thereby enabling the tool assembly to be readily inserted and operated merely by disconnecting the connecting rod and without the removal of the crank shaft from the main bearings of the engine.

Crank shaft bearings, particularly in internal combustion motors, become oval in cross-section from wear, and it has been the practice heretofore, in truing-up worn hearings, to remove the crank shaft from the engine and place the same in a turning lathe rinding machine to true-up the hearing to a circular form in cross-section. Usually, the major axis of the oval exceeds the minor axis by about five or six thousandths of an inch. VJ hen the bearings are trued-up by the old methods, about for to fifty thousandths of an inch of material is removed or ground off, which greatly reduces the diameter of the bearing and usually requires the use of new bearing boxes. By my invention, however, only the excess metal along the major axis is removed, which amounts to about live or six thousandths of an inch of material, thereby obtaining a large saving of material usually lost by the old processes of bringing the she ft to a uniform circular form.

(Ether objects ofmy invention will more fully appear from the following specification and upon the accompanying drawin Referring; to the drawing:

Fin 1 illustrates a top plan view of the tool assembly with parts shown in broken section:

Fig. 2 is a view showing the manner of introducing and placing the tool about a bearing of a crank shaft in an automobile engine;

F 3 is a sectional. view thetool;

Fig. 4; is a detail fragmentary view of a portion of anautomobile engine and a crank shaft in place therein, showing the tool in place when in operation upon a bearing of the shaft; and

Fig. 5 is a detail end view showing: the mode of keying certain elements against rotation but permitting longitudinal movement thereof.

Referring more particularly to the draw ing, in which the same reference characters are used to designate corresponding parts in the several views, the tool assembly therein shown is of annu ar f rm; comprising a pan of a portion of V nular port ens abut of metallic, preferably aluminum, semiannular members 1 and 2, secured together by a hinge member 3 about which the semiannular members are adapted to relatively rotate to open the tool assembly when de sired, and as is more fully disclosed hereinafter. Diametrically opposite the hinge member and at the other ends of the semi.- annnlar members, are provided integral radially extending; semicylindrical members 4 and which may be brought together to term a sort of handle or projecting means by which the tool may be manually operated, as will appear more "fully hereinafter, Both the members at and 5 are provided with alined apertures, the aperture 6 being tapered to receive the tapered shank of a pin 2" and the aperture 8 being of suliicient size to receive the stem 9 of the pin 7 upon the threaded end of which is mounted a thumb nut 10 adapted to press or operate against the member 4- in order to maintain the members 4 and 5 compressed togethe The semiannular members i and 2 are of channel form and are provided with a pluralit-y of radially extending apertures in which are disposed radially morable cutter shanks 11, at the inner end of each oi which is rigidly mounted a head 12 in which is mounted a cutting element 13 constructed of suitable tough and strong cutting material, such as high grade steel. The head 12 may be connected to the shank 11 by means of a tongue 14 preferably disposed at an angle to the plane oi the tool assembly, and the cutting element 13 is preferably maintained in the head 12 by fused material, or in any other suitable manner. The rear end of the shank 11 is provided with a longitudinal slot 15, adapted to receive a fiat key 1.6 of segmental shape disposed. in the slot 17 prmided in the periphery of the members i and 2, said key being adapted to prevent axial rotation or turning of the shank ll, as well as the members supported thereby, but permitting longitudinal movement of the same. The key member 16 is rigidly maintained in place by small upset or iammed portions 18 of the metal of the periphery of the members 1 and 2, these upset portions being formed by the impact oi. a suitable tool to cause the edges of the metal to project over the outer edge of the key 16.

Each shank provided with a plurality of transver ridges l9 and grooves adapted to cooperate or mesh with counter part grooves and ridges 19 and 20cn a spiral plate 21. This plate is preferably flat and annular in shape and consists of two semiannular partswith their ends normally in abutting Contact when the tool is in closed condition. lVhen the ends of said semian- 7 1'' each other, as when the tool is in closed condition, an endless ring or spiral plate is substantially formed which is adapted to operate upon all of the shanks 11. when such spiral caused to rotate or turn about the common axis of the tool and ring. The spiral plate may be provided at its periphery with a guide tongue 22, fitting in a groove 22 provided in the peripheral portion of the members 1 and margin of the spiral plate members may rest upon the surface 23 Of the channel members 1 and 2, as is clearly shown in l 21-. il-ach of the portions of the spiral plate 21,1nay be provided with a perforation 2a adapted to receive the lugs of a spanner wrench, whereby the plate may be caused to rotate in the tool assembly, the spiral 19', 20 thereof causing the shanks 11 to move radially inwardly or outwardly, depending upon the direction of rotation of the spiral plate.

The cutters 13 may be provided with a slight bevel, as shown in Fig. 1, which may be also slightly ooncaved if desired.

In Fig. 2, l have shown a crank shaft bearing 25 of a crank shaft mounted in its position in an engine with the tool partly in place and in open condition, a portion or the tool beinginserted within the engine casing in contact with one side of the bean ing 25 and the other portion being in position to be raised to closed position to contact with the other side of the bearing prior to the truing-up operation. The connecting rod 26 is normally connected at one end to the wrist pin of the piston referredto above (not shown) but is disconnected at the other end from the bearing and moved to one side in order to give clearance for the tool.

In Fig. 4 is shown, on a smaller scale, the same portion of the engine crank shaft with the tool in operative position on the hearing. The tool is relatively thin and adapted to be rotated about the bearing between The inner the arms 27 and 28 without any part of the tool contacting therewith.

In operation, the oil pan attached to the bottom of an engine casing may be removed, the connecting rod 26 disconnected'from the bearing 25 and the crank shaft suitably turned or moved in its main bearings to lower the bearing 25'to-itslowest position, if that is found necessarygfor the introduction of the tool. The tool is then opened by removing; thenut 10 fromthe pin 7 and the members 1 and 2 with the parts carried thereby, angularly separated about the pivot or hinge member 8 so as to assume the open condition as shown in Fig. 2. i To avoid any portion of the spiral ring projecting from the member 1 or 2 and interfering with a proper opening of the tool, the spiral ring is preferably rotated to bring the ends of the semiannular portions thereof into 00- inoidence with the respective ends of the semiannular members 1 and 2, after whlch the tool may be readily opened as above indicated. The tool may be then raised into the space in the engine casing so as to bring one of the members, such as member 2, in contact with the bearing 25 at the rear thereof, and then the member 1 raised to close the same about the front of the bearing 25, after which the pin '7 may be placed in the apertures 6 and 8 and the thumb nut 10 threaded to the end of the pin 7 to maintain the members 1 and 2 in closed position. he connecting rod 26 being moved to one side in order to make a clearance for the tool when the same is rotated, the operator or the mechanic may then rotate the tool by hand, or by any other suitable means, if desired, and at the same time may also apply a spanner wrench to the spiral ring 21 so as to cause the same to turn, whereby the spiral grooves and ridges thereof, meshing with the ridges and grooves of the shanks 11, will cause the latter to move radially inwardly as the rotation of the tool progresses, the bearing being acted upon by the cutting elements 13.

it will be apparent that as the tool is relatively thin it may be readily positioned between the arms 27 and 28 of the crank shaft respectively adjacentthe ends of the hearing 25 so that no part of the tool will interfere with the arms 27-and 28 as the tool is rotated about the bearing. it will be further observed that the effective cutting portions of the elements 13 are located along diametric lines so that the pair of cutting elements opposedto each other will always maintain the tool in centered position relative to the center of the shaft or hearing 25, irrespective of how much material is being cut. While such pair of elements cutting material, other of the elements which may or may not be cutting, or merely bearing against the surface of the shaft, will act as guide members. There is a certain amount of elasticity in the metal parts, particularly the members 1 and 2,

whereby the elements not operating as.

cutters at any time during the rotation of the tool, will, however, be caused to bear on the surface of the bearing and act as guide members until they arrive at points at which they may obtain a purchase upon the metal to be cut and thus perform a cutting operation. In previous devices, it has been necessary to provide separate means from the cutters to guide the cutting tool relative to the surface to be operated upon. These guiding elements usually are flat at their ends, although, in some cases, slightly convex, and chips or burrs cut from the material by the cutters, frequently are caught between the surfaces of the bearing and the guiding element and are jammed therebetween, causing either a marring or scarring of the surface of the hearing, or a movement will operate as guide elements on the surface cut by the preceding elements i and thereby maintain the tool assembly properly centered. It will be observed, however, that the cutting elements 13 will also act as guides on the surface they cut while performing a cutting operation, thus aiding the other elements to maintain the tool properly centered.

By the use vof my invention in the manner stated ordinarily only about five or six thousandths of an inch of material is removed, before the bearing is brought to circular form. The operator rotates the tool so as to first remove the excess material of the oval portion along the greater diameter thereof and just as soon as the cutters have removed the same and the hearing has reached a circular form, the diameter of which is equal to the smaller diameter of the oval, the operator perceives the same by the feel of the tool on the bearing and at that instant he knows that further removal of material. is unnecessary since the bearing has attained its correct circular form.

1: fter the operation is complete, the thumb nut 10 may be'removed and the tool opened and removed from the engine, the shaft rotated to be connected to the connecting rod 26 and the bearing put into operation as before.

While I have herein described and illus trated upon the drawing one embodiment of the invention and a mode of using the same, it is to be understood, however, that said invention is not limited to the particular details described and shown, nor to the particular use disclosed, but that other forms and uses are comprehended by said invention as dov not depart from the spirit of the invention and the scope of the appended claims, 7 I p Having thus described my invention, what I claim and desire to protect by Letters Patent of the United States, is:

1. In a tool for operating upon bearings, the combination of hinged semiannular members, radially movable members mounted in said semiannular members, cutting elements carried by said radially movable members and disposed in circular order, semi-annular members having spiral Operating elements mounted upon said hinged semiannular members, and movable therewith about-the hinge thereof, sald elements engaging said radially movable members whereby upon rotation of said semi-annular members radial movement is imparted si multaneously to all of said radially movable members. 7 v

9. In a tool for operating upon bearings, the combination of a diametrically split circular frame, a diametrically split annular member mounted upon said frame and adapted to rotate about the common axis of said frame and said ring, diametrically opposed cutters disposed in circular order about said axis, radially disposed holders for said cutters movably mounted in said frame and adjacent said ring, enmeshed spiral grooves and ridges on said ring and on said holders whereby angular movement of said ring about said axis causes a simultaneously radial movement of all of said holders and cutters, means for hinging the split portions of said frame whereby said portions may be opened for placing the tool about a bearing, and means for securing said portions in closed condition. 7

3. In a tool for operatingupon bearings, the combination of a sectional hinged annular frame adapted to encompassa bearing, cutting elements supported bysaid frame, and means for adjusting all of the cutting elements simultaneously towards or away from the encompassed bearing.

4 In a tool for operating upon bearings, the combination of a sectional hinged annular frame adapted .to encompass a bearing, a plurality of respectively diametrically opposed cut-ting elements, radially disposed holders for supporting said cutting elements movably mounted in said frame, and sec tional adjusting means movably mounted on said frame, and in engagement with said holders whereby a movement of said means relative to said frame causes a simultaneous radial movement of all of said holders and cutters in unison.

5. In a tool for operating upon a bearing, the combination of opposed abuttingsemiannular frame sections, means for hinging said sections whereby said sections may be angularly separated, means on said sections opposite from said hinging means for securing said sections in closed abutting relation, opposed abutting semiannular ring sections carried upon said frame sections and adapted to be angularly separated upon the relative movement thereof, cutting elements dis posed in circular and diametric relation, and holders for supporting said cutting elements movabl y mounted in said frame sections and movable therewith, said holders and said ring sections having enmeshing spiral grooves and ridges, and said ring sections when abutting forming a continuous circular spiral ring which upon rotation causes a simultaneous radial movement of said holders and cutters in unison.

6. A tool for operating upon crank shaft bearings comprising a relatively flat circular frame formed of hinged sen'iiannular sec tions adapted to be angularly separated for the placing of said frame about a bearing to be operated upon and adapted to be inserted and rotated between the connecting crank arms at both ends of the bearing without interfering, with said arms, cutting'elements carried by said frame, and means on said frame in engagement with said cutting elements for simultaneously radially adjusting all of said cutting'elements relative to said bearing.

7. In a tool for operating upon bearings, the combination of semiannular frame sections, hinge members projecting therefrom and 'pivotally connected together whereby saidframe sectionsmay be angularly separated or brought into closed orv abutting re lation, locking projections on said frame sections opposite from said hinge members, a locking pin for securing said projections together, cuttingelements in diametrically 0pposed and circular relations, holders for said cutting elements comprising cylindrical shanks longitudinally movable in radial bores provided in said frame sections, said shanks being slotted at an end thereof,means passing through said slotted ends and fixed to said frame section for preventing said shanks from rotating about their respective axes, and semiannular ring sections on said frame sections adapted to abut each other to form a continuous circular ring when said frame sections are in closed or abutted relation and adapted to be separated when said frame sections are angularly separated, said ring sections and said shanks provided with enmeshed spiral grooves and ridges whereby movement of said ring sections causes a radial movement of said shanks and cutting elements in unison.

Inwitness whereof, I have hereunto set my hand this 17th day of May, 1920. j

j KARL R. PETERS. 

